In a modern internal combustion diesel engine, the load carrying part of the engine is referred to as the（）

A.water in the fuel
B.insufficient fuel for combustion
C.clogged air intake passages
D.burning lubricating oil

A.increased horsepower
B.reduced efficiency
C.increased heat loss
D.lower cylinder pressures

A.dangerous over-speeding
B.a loss of lube oil pressure
C.activation of the fixed CO₂ system for the emergency generator space
D.all of the above